Before joining a new betting site, verify its licence on the UK Gambling...

https://mike-wiki.win/index.php/Why_do_UK_players_compare_mobile_betting_sites_more_than_desktop_now%3F

Before joining a new betting site, verify its licence on the UK Gambling Commission register. Read bonus terms closely, including the 10x wagering cap for licensed operators, then check mobile usability and withdrawal times